PDF Compression
Reduce your PDF file size while keeping document quality intact. A fast, free online compression tool.
Share this page
Thank you for using our service!
Sharing this site with your friends would be a huge help.
How to compress PDF files online for free
- 1Click the 'Select File' button to upload a PDF file, or drag and drop the file onto the tool screen.
- 2If needed, you can add multiple PDF files at once.
- 3Select the compression level (High, Medium, Low), then click the ‘Compress PDF’ button to start.
- 4When processing is finished, click ‘Download’ to save the compressed PDF file.
Key features
Fast processing speed
Reduce PDF file size in just a few seconds with a high-performance compression engine. It efficiently cuts only the size while keeping the quality intact.
Unlimited free use
Anyone can use it for free without signing up. There are no limits on the number of compressions or file size.
All features included
Along with file compression, it also provides various PDF features such as merging and rotating.
Enhanced security
All files are encrypted and processed securely, and are automatically deleted within 1 hour after upload.
Easy to use
No expertise needed—compress with just one click. Anyone can use it intuitively.
Cross-platform support
Windows, macOS, Android, iOS—use it instantly on any device as long as you have a browser.
Why you need PDF compression
PDF files can become large because they include images, fonts, graphics, and more. If attaching by email or uploading is difficult, compression can make them much lighter.
PDFNavi’s compression tool reduces file size without degrading quality. With automatic optimization, it can reduce size by up to 90% while preserving document clarity.
In addition, all processing is encrypted, and after a certain time the files are completely deleted from the server. You can protect both privacy and file security at the same time.
Guide to choosing the right compression option for your situation
When reducing PDF file size, it’s important to find the right balance between 'size' and 'quality'. PDFNavi provides three tailored compression modes based on your purpose. Rather than making the file as small as possible, choosing the option that matches your use case produces the best results.
By checking the 'Estimated size' shown in the preview before compression, you can conveniently gauge how much smaller the file will become.
- Balanced compression (recommended) The default option best suited for most users. It efficiently reduces file size while maintaining readability and image clarity. Perfect for email attachments and web posting.
- High quality (lower compression) Use this for portfolios with high-quality images or documents intended for print. The size reduction is smaller, but it preserves the original quality as much as possible.
- Maximum compression mode Useful when you need to reduce file size extremely rather than image quality. For text-heavy documents or files kept simply for reference, it can significantly reduce the size.
Email failed to send? Tips to handle attachment size limits
Have you ever had an email fail to send due to an 'attachment size limit' at work or when submitting an assignment? Many corporate or portal email services limit attachments to around 10MB–20MB. In those cases, a PDF compression tool can be the fix.
Reports that include scanned documents or many high-resolution photos can easily exceed tens of MB. With this tool, you can reduce them to a sendable size in seconds without installing any additional software.
- You can upload multiple PDF files at once and compress them in bulk, improving work efficiency.
- If the file is still large after compression, try 'Maximum compression mode' or delete unnecessary pages and try again.
- Even on smartphones (Android, iOS), you can access via the browser and handle urgent documents right away.
The principle of compression and the secret to preserving quality
Ever wondered, “How can the size be smaller while the content stays the same?” PDFNavi’s compression engine removes invisible unnecessary data (metadata, duplicate font info, etc.) and optimizes image resolution (DPI) based on your purpose.
As a result, text readability remains the same while the overall file becomes lighter. It’s not just resizing—because it analyzes and optimizes the document structure, you can use it with confidence.
- Text information is preserved as vectors, so characters remain sharp without breaking after compression.
- Image data is compressed intelligently within a range that minimizes visual differences.
Frequently Asked Questions (FAQ)
What if the quality of the compressed file drops too much?+
If you’re not satisfied with the result, change the compression option to 'High quality (lower compression)' and try again. If you need an even smaller size, choose 'Maximum compression mode'.
Are there limits on how many times I can compress per day or on file size?+
No. PDFNavi is a 100% free service and does not impose artificial limits on daily usage or upload size. Use it as much as you need.
Is it safe to upload personal documents or confidential company materials?+
Yes. All transfers use SSL-encrypted connections, and both the original and compressed files are automatically and permanently deleted within 1 hour after processing. Even administrators cannot open your files, so you can feel safe.
Can I use it on a Mac or iPad?+
Yes. Because it’s a web-based service with no app installation required, it works perfectly on Windows, Mac, Linux, as well as iPhone, iPad, and Android tablets—any device with internet access.
Can I compress an already compressed PDF again?+
Technically yes, but re-compressing an already optimized file will rarely reduce size and may only worsen quality. We recommend compressing once from the original file with an appropriate option.
